An innate design sensibility shines through a furniture showroom when the proprietor and her family live upstairs.

Tina Seidenfaden Busck: I had been acting as an interior design and art adviser for private clients for a while and wanted to create a space where I could showcase a curated selection of vintage pieces as well as works of the contemporary designers whom I admire. The idea of creating the Apartment, a gallery laid out like a private home, took form when this place—an 18th-century, 2,600-square-foot apartment in Christianshavn in dire need of renovation—became available. I want the Apartment to look and feel like a place where people can imagine sitting down to dinner or reading a book. The same goes for my own home [two floors up]: I like the fact that you can see that we all live there—me, my husband, and our three children—plus all the quirky combinations that come with being a family. The Apartment has a very classic Hammershøi-like layout, with wood paneling, original hardwood floors, and lots of light. My own home has a slightly less classic feel: It’s a duplex with sloping walls and an open-plan layout.

In the dining area of the kitchen, a Mobile Chandelier 3 by Michael Anastassiades is suspended above a table from local cabinetmaker Københavns Møbelsnedkeri. Vintage red dining chairs by Ralf Lindberg mingle with an Ilse Crawford bench for De La Espada. Photos courtesy the Apartment.

My father was a fashion designer; he was very into decorating our home, and he used a lot of colors. And I grew up in a family that collected contemporary art, so I’ve always been going to auctions. My ten years at Sotheby’s and time at Andersen’s Contemporary—representing artists like Olafur Eliasson and Tomás Saraceno—have given me a good in-depth knowledge of today’s art and design market.

The front parlor is a visitor’s first hint of the mix of furniture Tina Seidenfaden Busck has assembled for her showroom the Apartment. A pouffe from Azucena is matched with an array of vintage pieces: a Beni Ourain rug from Morocco, a mirrored chest of drawers from France, and a Finn Juhl Poet sofa. The next room houses a vintage Tulip table and chairs by Eero Saarinen and a Tube Chandelier by Michael Anastassiades. Photos courtesy the Apartment.

At the Apartment, I aim to showcase beautiful objects that maintain and increase in value over time. I have an eclectic taste, although with a very soft spot for Italian and Swedish design from the 1950s. Designs [from those eras and regions] have an experimental and friendly edge to them that I like, not to mention exquisite craftsmanship and materials.

A Gio Ponti chair from 1963 is paired with a vibrant Daniel Lergon painting and Ball Lights by Michael Anastassiades, all set off against All White paint from Farrow & Ball. Photos courtesy the Apartment.

There is no such thing as a “perfect” mix. However, the main components at the Apartment and in my own home are a mix of 20th-century vintage furniture and selected contemporary pieces, like McCollin Bryan’s Lens tables, lighting by Michael Anastassiades, vintage Berber rugs and patchwork quilts, and rattan. I love the way rattan was used in the mid-century to create elegant and accessible furniture. I’ve also been collecting contemporary art forever, and art is a dominant feature in my own home—together with our book wall and lots of souvenirs important to our family. In short: Keep it personal and try to incorporate elements with history that’s significant to you.

A Danish sofa, designer unknown, is set against an accent wall painted in Stone Blue by Farrow & Ball. As the local dealer for Anastassiades, the Apartment contains various pieces of his work, including the Mobile Chandelier 5 (2011), the Ball vase in cast brass (2006), and the wall-mounted Beauty Mirror (2010). The vintage Boucherouite rug is from Morocco. Photos courtesy the Apartment.

I of course appreciate Danish modern. That heritage is a very big part of our DNA in Denmark. But having worked and lived abroad for many years, I fell in love with foreign designers. And Finn Juhl and Arne Jacobsen would not have been who they were—masters—without also looking abroad.

In the living room, furnishings include a cherry-wood dresser by Rune Bruun Johansen, a vintage wicker lounge chair from Italy, and a Ludvig Pontoppidan settee. The round Lens table is by McCollin Bryan. Lighting includes a circa-1950s Venini Poliedri chandelier and French floral wall sconces from the 1930s. Photos courtesy the Apartment.

One of my favorite aspects of running the Apartment is being able to work with contemporary designers, like Michael Anastassiades, whose work I respect immensely. The timelessness of his designs, the outstanding craftsmanship and exquisite materials. I am so happy to show his work in Scandinavia. We also exhibit Ilse Crawford’s furniture collection for De La Espada—I’ve admired her interior designs for years. For more avant-garde pieces, we carry McCollin Bryan, two English designers with a distinct, playful approach to design and an uncompromising quality.

The attenuated Tree in the Moonlight floor lamp was designed by Anastassiades in 2010. Photos courtesy the Apartment.

Small spaces require functional furniture more than larger spaces do, but they also enable you to create a much more dramatic interior. You can make them very dark or very light, very playful or very formal. Overall, these spaces should hold only a limited amount of furniture—for instance, a daybed, a foldout table, an eye-catching ceiling light, or wall-mounted sconces.

People undervalue lighting. It gives a lot of atmosphere and creates coziness. With a mix of table, ceiling, and floor lamps, you get light coming from various angles. You can decide what to have on in the daytime and the evening, then play with the theme. In the Apartment now, we combine a 1950s Italian glass pendant with Azucena floor lamps, a Michael Anastassiades tube wall light, and LED lights from Le Deun Luminaires. This fall, Flos is doing a limited edition of Achille Castiglioni’s Snoopy table lamp especially for us, and I can’t wait to get one for my own study.